Subject: [mg122659] How to evaluate parts of an expression, but not other parts?

From: Julian Francis <julian.w.francis at gmail.com>

Date: Sat, 5 Nov 2011 04:45:28 -0500 (EST)

Delivered-to: l-mathgroup@mail-archive0.wolfram.com

Dear all,
I'd like to use the TreePlot function to visualise the expression of a
dynamic programming problem I am working on.
If I have something like: ( (a+b) + (c+d )
Mathematica helpfully simplifies this to: a + b + c + d
But I'd prefer it to be in the original form.
I can't write Hold[ ( (a+b) + (c+d) )] because I do want a,b,c & d to
be evaluated.
I want to write something like:
Hold[ ( (Evaluate[a]+Evaluate[b]) + (Evaluate[c]+Evaluate[d]) ) ]
But this just leaves the Evaluate expressions unevaluated.
Any help greatly appreciated.
Thanks,
Julian.